Expert explains how trains can derail

As derailed trains continue to cause alarm and damage across communities, Channel 11 is digging deeper into what causes them.

Related coverage >>> 9 Norfolk Southern cars derail in New Castle

According to national data, human error was the leading cause of train derailments in 2022. Track defects were the second-most-common cause.

11 Investigates is learning more about train mechanics and how other issues may cause or worsen derailments.

PHOTOS: Norfolk Southern train derails in New Castle

Jared Cassity, Chief of Safety with “SMART,” the largest union representing railroad workers in the United States, likens a train’s movement to that of a “slinky.”

“When you pull a train, that one car moves. It gives a space that the next car grabs and moves with it,” he explained, adding that longer trains can present even more of a challenge.

“When you’re going over hills, your train may be separate or stretched out on the backside of it and bunched up on the front side.”

Problems can result depending on how the weight is dispersed. If a train is heavier in the rear, Cassity says “you can now imagine that slinky with a 10-pound weight tied to it. It’s easier to get it moving, but when the 10-pound weight comes in, you feel that lunge... once you’re moving, it’s not too bad. But, if you want to stop... that tonnage just comes crashing in.”

As for the Norfolk Southern train that derailed on Wednesday night, it could be months before investigators determine what caused it.

As Channel 11 reported, 9 cars derailed toward the rear. Several of them on a bridge over the Mahoning River were empty.

In total, there were 213 cars and three locomotives, according to a company spokesperson. The spokesperson has not stated how long the train measured.

According to the Association of American Railroads, recent legislation defines a “long train” as 7500 feet, adding “railroads have operated millions of trains exceeding that length without incident or notice for the past 80 years.”